In the early 2000s, Keerthy worked as a child Actress in a few of her father's productions, such as Pilots (2000), Achaneyanenikkishtam (2001) and Kuberan (2002) and some television serials. 11 years after Kuberan, she made her debut as a lead Actress in Priyadarshan's horror film Geethaanjali, in which she had a dual role. She was still studying during that time and shot for Geethanjali during her semester break. Reviews on the film and her performance were mixed, with Sify writing that she "does put in some effort but makes only a limited impression in a double role", while Rediff wrote that she "has got a plum role but whether she impresses with her acting prowess is another matter". In 2014, Keerthy had her next release Ring Master, directed by Rafi of Rafi Mecartin duo, in which she shared screen space with Dileep. She played the role of a blind girl, which she said was much more challenging than her double role in Geethanjali. The film was a commercial success, being termed a "super hit" by Sify.
As of 2014, Keerthy has completed shooting for the art film Darboni, in which she would be seen as a Kashmiri girl. Besides, she is part of Paambhu Sattai in Tamil, in which she plays a poor Chennai girl from a lower middle class strata, and Nenu Sailaja in Telugu. She has also signed up a film with Suriya titled Thaana Serndha Kootam, directed by Vignesh Shivan and lead female role in Saamy 2, The Sequel of Saamy, opposite Vikram and Second Lead Trisha Krishnan. Also, she will be portraying the late southern Actress Savitri, in her Tamil-Telugu bilingual biopic titled Mahanati, directed by Nag Ashwin, which is yet to begin production.